[Grave Raiders Notes bg] Lost Notes 2: Heavy Fate

Hanshan Temple outside Gusu city, the bell to the passenger ship at midnight.

Midnight refers to Zishi.

"The time reported just now is Xu time, and there are still four hours before Zi time." Zhang Qiling looked at the more and more nematodes gathering at the bottom of the water, returned to the water and swam towards Nanxing, "You guys go to the high platform first, I'll guard the door."

Zhang Qiling came to Nan Xing and motioned for her to go in, but Nan Xing didn't move, Zhang Qiling said: "The water in this room must be filled to the point where it can support the water tank to run for four hours, and there will be more and more nematodes inside."

But Zhang Yuetong and the other three teenagers need to keep reapplying Qilin blood to defend themselves. It is the safest way for them to go to the high platform.

"Maybe you don't need to fill it all up." Nan Xing fixedly looked at the hole on the wall of the room leading to the mechanism, thoughtfully, "I can finish the calculation as quickly as possible."

"Yuetong, do you all remember the length of your arms?" Nan Xingchao asked Zhang Yuetong who was still in the water.

Several people looked at Nan Xing suspiciously and nodded at the same time.

"Okay, now I need your help to measure the length and width of the room, and tell me the result immediately after the measurement." Nan Xing took the lead and plunged into the water after speaking, swimming towards the hole.

After he measured the height of the hole from the bottom of the room and surfaced, Zhang Yue and the others just finished measuring the size of the room.

"The long side is 20 meters."

"The short side is [-] meters."

"Okay, then it can be assumed that the height to which the water needs to be filled is h0, and the time is started after it is filled. The time is recorded as t, the real-time water surface height is h(t), the room area is S1, and the water outlet hole area is S2. After closing the door, the water level in the room drops The velocity v1 of the hole, the velocity v2 of the water flowing out of the hole, then according to the Bernoulli equation, we can know:

1/2ρv1(t)^2+ρgh(t)+p=1/2ρv2(t)^2+p

where P is atmospheric pressure.

From the incompressibility of liquids we know:

v1(t)S1=v2(t)S2

∫v2(t)S2dt=S1[h0-h(t)]

Considering S1>S2, the formula can be simplified as follows:

ρgh(t)+p=1/2ρv2(t)^2……(1)

v1(t)S1=v2(t)S2……(2)

∫v2(t)S2dt=S1[h0-h(t)]……(3)

Combine formulas (1), (2) and (3) to get:

h(t)=(√h0)-(S2/2S1)(√2gt)

当t为两个时辰时，h(t)=0，则h0=2gt(S2/S1)^2=0.9（m）

Therefore, the height of the water surface we need is 0.9 meters. Although I ignored the viscosity and surface tension of the water when I calculated, we can round up to 1 meter to eliminate this effect. After Nan Xing finished counting in one breath, he turned around and measured the position one meter above the hole on the wall, and engraved a mark on it, "Brother, I will guard the next meter with you. Don't persuade me to go up first. I don't listen. "

Zhang Qiling: "I have no intention of persuading you."

Nan Xing: "...No, my emotions are already brewing, why don't you persuade me?"

Zhang Qiling glanced towards the high platform: "They can just go up."

Nan Xing turned around and saw Zhang Yuetong walking up the steps by the collars of several teenagers, and Zhang Haiyin was holding the unicorn blood jar Nan Xing left behind.

Zhang Qiling glanced at Nan Xing's palm, there was no scar on it.

The blood in the jar was drawn by her privately with a syringe and stored.

He looked away, looked at the gradually rising water level in the room, and said in a deep voice: "The water in the room flows into the mechanism through the hole to drive the water to move the muddy phenomenon, but at the same time, the nematodes will also flow in through the hole. The few of them will be fine on the high platform, but it is impossible to predict what will happen next, unless it is absolutely necessary, you should not let bloodletting."

You don't bleed any more.

This sentence is so familiar...

It seemed that in that distant memory, he also said the same thing to her.

Under what circumstances did he say it?

Why was she so impressed by this sentence?

Nan Xing kept searching in her mind along the traces of that distant memory, and more and more memory fragments, like thousands of crystal clear snowflakes, fluttered and filled her whole world, falling on the ground bit by bit and gradually pieced together more and more. The more and more complete continuous memories are finally connected with the scene when I woke up in the snow in Medog when I was young.

Nan Xing seemed to have returned to that cold morning 20 years ago, when she was lying in the boundless snow, in front of her was the voice and appearance of Zhang Qiling from her previous life.

The cold and indifferent man who bore his fate alone in his previous life gradually overlapped with the peerless silhouette in front of him. Those deep and indifferent eyes passed through a hundred years of heavy years, and he looked at Nan Xing peacefully.

Nan Xing took a deep breath, lowered her slightly red eye sockets, "Then you also promise me that you won't let bloodletting again."

Zhang Qiling didn't say anything.

The silence beside him was a bit longer, Nan Xing looked up suspiciously, "Promise me quickly."

"Enough water, let's go." Zhang Qiling didn't answer her, raised his hand and pulled the huge black door in, and the door closed with a "bang".

Nan Xing looked at his back, she knew better than anyone else that he would not agree to her.

Just like herself, when faced with a situation that required unicorn blood, she would definitely cut her own palm without hesitation.

The author has something to say:

Today's toast to Fluid Dynamics!

Jinjiang can’t write the root sign, so use √ instead~

Thank you for the 10 bottles of nutrient solution provided by Ying Fen Irrigation!I love you love you love you!